uobjnew traces object allocations in high-level languages (including "malloc") and prints summaries of the most frequently allocated types by number of objects or number of bytes.

This tool relies on USDT probes embedded in many high-level languages, such as C, Java, Ruby, and Tcl. It requires a runtime instrumented with these probes, which in some cases requires building from source with a USDT-specific flag, such as "--enable-dtrace" or "--with-dtrace". For Java, the Java process must be started with the "-XX:+ExtendedDTraceProbes" flag.

Object allocation events are quite frequent, and therefore the overhead from running this tool can be considerable. Use with caution and make sure to test before using in a production environment. Nonetheless, even thousands of allocations per second will likely produce a reasonable overhead when investigating a problem.